// A circle.
public class Circle extends Shape {
	
	// The radius of this circle.
	public int radius;
	
	// Constructs a new circle with the given radius 'r'.
	public Circle(int r) {
		radius = r;
	}
	
	// Returns the area of this circle.
	public int getArea() {
		return (int)(Math.PI * radius * radius);
	}
	
	// Returns a string representation of this 
	public String toString() {
	
		// Notice that we are using the toString() method inside
		// Shape (Circle's superclass) to construct part of our string.
		return super.toString() + "; radius = " + radius;
	}
}